


BOOK THREE: INFINITY WAR

by Zodia



Series: Infinite Hero AU [3]
Category: The Avengers (Marvel) - All Media Types, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: F/F, F/M, Gen, M/M
Language: English
Status: In-Progress
Published: 2020-08-30
Updated: 2020-09-08
Packaged: 2021-03-06 21:34:21
Rating: Mature
Warnings: Major Character Death
Chapters: 3
Words: 3,980
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26185762
Author URL: https://archiveofourown.org/users/Zodia/pseuds/Zodia
Summary: Two weeks after saving Eri from Overhaul; Mirio, Nighteye, All Might, Amajiki, Fat Gum, and serval other heroes uncover the truth of what really happened to Izumi. And now signs are pointing to a war left unfinished, a war between the Avengers and an old foe by the name of Thanos.
Relationships: Amajiki Tamaki/Kirishima Eijirou, Midoriya Izuku/Toogata Mirio
Series: Infinite Hero AU [3]
Series URL: https://archiveofourown.org/series/1897246
Kudos: 29





	1. Prologue: The Dream

**Author's Note:**

> Welcome to Book 3 everyone!

In the two weeks following the aftermath of Izumi, Kirishima, and Goose saving Eri from Overhaul; Izumi has been placed in a specially designed bio-tank keeping her heavily sedated as the biggest brains of the Avengers work non-stop to make improvements to the latest collar they have designed for her.

“Tell Rodgers, did you take my niece in out of pity or did you take her in to use her?” Asked Nighteye now having a chance to speak with super solider.

“Neither believe it or not. I saw a girl who needed a family, so I brought her into my family.” Steve answered.

“I believe you. For now.” Nighteye as he gazed onto his niece sleeping with breathing mask on while she remained in the bio-tank. “How much longer do they intend to keep her in there?”

“Until the collar is done.” Steve said looking down upset.

“Do the injuries still hurt?” Nighteye asked.

“No, the burn wasn’t as bad as it looked.” Steve answered losing his upset look gazing at Izumi.

**“I am Groot.”** Groot came into the room.

**“Groot.”** Steve greeted. “Mirai Sasaki, meet Groot he is Izumi’s best friend and he can only say “I”, “am”, and “Groot” and in that order.”

“Truly?”

“Only Rocket, Thor and Izumi can understand him.” Steve explained. Nighteye nodded before turning to look at his niece. He saw Groot grow flowers out of his hands and wrap them in a twine like string he made placing the bouquet next to the tank.

 **“I am Groot.”** He said once before leaving.

////

Mirio was training in the HARM room with Amajiki, Nejire, Kirishima, and the Black Panther; or T’Challa as Kirishima called him. He offered to help them blow off steam since they had been stressed out over the events of two weeks ago. And if there one thing that the Big 3 of UA learned about the Black Panther was, he was strong and wise too.

“Not, bad Togata. But you’re too brash you can’t always rely on punching your way through.” T’Challa informed him.

“R—Right!” Mirio said. Suddenly Kirishima came out nowhere nearly beheading T’Challa how managed to block it. He twirled Kirishima in the air as the young redhead landed on his stomach with a soft groan. He jumped back up and the two got into a fist fight while the Big 3 just watched in awe.

“You know Amajiki you have to ask him out at this point. I mean look at him!” Nejire whispered.

“It’s not that easy!” Amajiki covered his face blushing. Mirio smiled at his friend patting him on the shoulder before going to join Kirishima.

**“T’Challa.”** Called Nebula.

**“Ah, Nebula, come to join us?”**

**“No, I thought I come and tell you that Izumi has been released from the tank.”**

**“Izumi has been released does that mean she’s awake!?”** Asked Kirishima in perfect English shocking the Big 3 of UA.

**“No not yet. She’s still heavily sedated, however they believe she’ll be awake tomorrow.”** Nebula explained then left.

“Hey, hey Kirishima what did she say?” Nejire asked.

“Izumi is out of the tank. But she’s still sedated but she should wake up tomorrow.” Kirishima told them. “Can we go see her T’Challa?”

“Sure.”

////

_This place it was black but there was this white airy smoke like clouds swirling in front of her face. Where was she?_

_“Beware young Rodgers….” Six lights of familiar colors appeared with in the white airy smoke. “He has returned…” The sight before her changed and she saw a tall man with purple skin. His right hand was covered in golden armor. “Beware young Rodgers…the final confrontation approaches…”_

Izumi woke with a gasp coughing as she went to sit up. Her body felt so heavy.

“Izumi!” Two voices called out to her. She looked with blurry eyes seeing her dad and Uncle Mirai on either side of her.

“Izumi breath, you’re okay.” Steve said.

“Nothing… going to be okay…He’s back…” She coughed as Steve’s eyes widened. “Th—Thanos…has returned…” She passed out. Steve was left frozen in shock.

“Mr. Rodgers?” Nighteye asked.

 **“FRIDAY call all the Avengers for an emergency meeting.”** He ordered.

 **“Right away.”** Said the AI.

“What’s going on Rodgers?”

“Come with me and you’ll find out.” Steve said.


	2. Chapter one: Who is Thanos?

Everyone, Fury, the Big 3, Kirishima, and the pros included all where in the Avengers’ meeting room of the tower. Steve told them what Izumi had said. The pros and the Big 3 noticed how even Kirishima tensed up at what they heard.

“Kirishima?” Fat Gum looked worried. Kirishima didn’t answer as the young man seemed to be contemplating what he had just heard.

 **“Who is Thanos?”** Asked All Might.

Fury sighed but it was Thor who answered with Tony translating it in Japanese, **“Thanos is a madman from some unknown corner of space looking to bring together the Six Infinity Stones so he can wipe out half the universe.”**

“But wasn’t it the same stones that gave Infinity Girl her power?” Asked Bubble Girl.

“Yes. But after the explosion we lost track of them and Thanos. We’ve been looking high, low, far and wide for them. But we’ve been coming up empty.” Said Tony.

“Is there a chance he might confuse Izumi for the stones?” Asked Nighteye.

“It’s a huge possibility.” Said Bruce. “Each of the stones has their own unique cosmic signature and Izumi can generate the same signatures depending on which power of Infinity she’s using. And after what happened two weeks ago, he most defiantly on his way here.”

“Which would mean what?” Asked Fat Gum.

“There’s going to be another war.” Said Kirishima shocking the pros and the Big 3. “Thanos is far to hellbent on wiping out half of all life in the universe to give up. And when it finds out that Izu’s power comes from the stones there is no telling what he could do to her.” Mirio and Nighteye looked mortified hearing Kirishima. Fury began discussing plans with the Avengers as Mirio slipped out of the meeting room. He needed to think.

/////

Sometime after leaving the meeting room, Mirio found himself at Izumi’s bedside. Goose was sleeping at her waist curled into a little ball.

“I don’t know if you can hear me and I probably shouldn’t be talking to you while you’re sleeping but I need someone to listen to me for a while.” Mirio began. “Mr. Rodgers passed along your warning. I and the others learned about this evil alien villain called Thanos. Fury is barking orders right about now... I’ll admit I’m scared knowing that I don’t know enough about Thanos and what he is capable of. I know that the Avengers will fill me and the others in. But when you wake up? What’s going to happen? What are you going to do?”

“I’ll stand.” Izumi woke up. “I’ll stand and fight that bastard.”

“That’s the spirit.” Mirio smirked. “Good to have you back Izu.”

“Sorry I worried you.” She sat up careful not to wake Goose. “So, now you know the truth of my past. Do you hate me for my dishonesty when you first asked?”

“No!” Mirio said. “Fury was very clear that you where under orders and we understand I promise.”

She giggled then looked out the window, “A war is brewing and there is no telling who will win. Will it be the Avengers or Thanos? Only time will tell. However, I am curious.”

“About?”

“What will _you_ do? Now knowing the truth and that a mad titian is coming to Earth looking for six very powerful stones will you fight, or will you run?” She asked him with a serious look on her face.

“I will fight.” He said firmly. “I will fight and protect. I am not running way I swear.”

“I’m going to hold you to that.”

“Please do and feel free to slap me again if it looks like I’m forgetting I made this promise.”

“Alright then.” She giggled.

/////

“Kirishima you’re really…?”

“I’m not going to turn tail and run Senpia. Especially from this.” Kirishima said. “I wouldn’t be able to forgive myself if I ran from something like this.” Amajiki looked down holding his arm. “Senpia…”

“Call me by my name.” He asked.

“A—Are you sure?!” Kirishima stuttered shocked.

“Yes.”

“Alright then Tamaki. Call me Eijiro.” He smiled.

Amajiki smiled softly. “You still owe me dinner for scaring me like that.”

“I was kind of hoping you forgot…” Kirishima said getting a mused look from Amajiki. Kirishima laughed lightly.

/////

Izumi was standing out on the balcony at the top of the tower looking at the Earth. She had been talking with Fury and the other Avengers about plans to combat Thanos and his followers. Izumi deiced to play as live bait keeping Thanos from looking for the stones.

“Are you sure about Little Lady?” Bucky asked.

“Does anyone have a choice anymore?” She asked. “We can’t let him get the stones wherever they are.”

“Good point. But you saw the look on your father’s face. Same with your Uncle Mirai. Neither of them is going to agree.”

“Willingly anyway.” Izumi corrected. “It’s not like I want to play live bait. Unless someone else comes up with a better idea it’s going to have to do for now.”

“Izumi,” Gamora came walking over.

“Aunt Gamora, what’s up?” Izumi asks casually.

“We need to talk, alone please.” She looked at Bucky. Bucky nodded and left the two girls on their own. He didn’t hear what they were talking about but figured it was related to Thanos.


	3. Chapter two: Love and Hela

Something that been bothering Thor recently. Kirishima knew enough to know that something was seriously bothering the Asgardian God. He tried asking but Thor always turned him away. Everyone was picking up on Thor’s new behavior and was finding it concerning.

“Thor its coming isn’t it?” Izumi asked one day as Kirishima, the Big 3, and the pros looked at her and Thor. 

“It is.” He answered earnestly.

“What are you talking about?” Asked Kirishima.

“Ragnarök.” Izumi answered. “The fabled foretold event that will destroy Asgard.”

“Thor…” They looked at the God of Thunder.

“Wait, how?” Asked Mirio.

“A demon of fire named Surtur will come to Asgard and rain his fury over the golden city.” Izumi explained.

“Hey, hey, what’s your plan Thor?” Asked Nejire. “I mean you gotta think of something to keep that from happening.”

“I’m not sure about that yet.” He said and closed his eyes deep in thought. “I’ll have to consult Odin before anything, the cosmos knows it shall be he who will have my head for rushing into battle without speaking to him first.”

“Would you like some company?” Asked Kirishima.

“No, this is something I must do alone I’m afraid. Ragnarök will only cause the destruction of Asgard not Earth.”

“But that does to mean Earth won’t be effected.” Said Sir Nighteye. “And the timing of this fated event is a little too convenient given the circumstances.”

“I have noticed that too. I know that my father will have some sort of answer.” Thor says walking outside to the garden. “Heimdall.” Suddenly a deep of light rained down on Thor and then he as gone. There were barn marks on the grown relating to Norse designs.

“What the…” Kirishima gasped.

“That was the Bifrost.” Izumi answered. “Heimdall is its keeper he is in charge of the passageways between the Nine Realms.”

“That’s so cool!” Said Mirio. “What’s he like?”

“Stoic and wise. He is very loyal to Asgard and will do anything to help save it.” Izumi explained.

“That is so cool!” Said Kirishima and Mirio.

“I wonder what the Bifrost looks like…” Said Nejire.

“Going off the legends probably it’s a rainbow.” Izumi said she then felt something. It was like a chill running through her body. She snapped her head to the earth with a serious expression.

“What’s wrong?” Asked Kirishima.

“I don’t know…but I have bad feeling. I’m heading to see Fury. I’ll be back.” She said disappearing into the Tower.

“I’m going to the HARM room and blow off steam.” Kirishima announced.

“Can I come?” Asked Fat Gum.

“Sure! Race you!” Kirishima said taking off. Fat Gum quickly ran after him as the others watched amused by the friendly race.

_Oh Eijiro…you really do shine like the sun…_

/////

Amajiki wasn’t sure if he should be doing right now but he wanted to know something. He walked into the lab and made a b-line to Dr. Banner.

“Hello Amajiki need something?”

“I was wondering if you could tell me more about Eijiro’s training.” He asked.

“That’s more of for the “other guy” but I can tell you what I know.” Bruce said nervously. “Kirishima’s quirk is actually the reason why he trained more with the “other guy” and the others. It was through the “other guy” that Kirishima was able to improve his quirk.”

“I see.”

“So, if you don’t mind me asking, you’re on first name bases with Kirishima?”

“Y—Yes. Since we’re working together, I just thought that it would be better. Like as a way to show him that I see him as an equal.”

“Oh sure.” Tony chimed in. “You know when he came to us after the first time you two worked together, he couldn’t shut up about you.”

Amajiki blushed, “R—Really!?”

“Really. He kept going on and on about how amazing you are.” Tony added. “To honest I think the rocky kid has got a crush on you and looks like the feeling is mutual.” Amajiki’s blush only got worst as a result. He did have a crush on Kirishima; a huge crush on the younger classman at that. Since the first day they met there was something Kirishima that drew him in. Maybe it was his sun like personality and that confident aura he had.

“You really think that he…”

“I allow me to correct myself,” Tony said. “I _know_ the rock kid has got a crush on you.” If there was thing about Tony that Amajiki knew was that Tony wasn’t a lair. During the two weeks of getting to know the insanely rich quirkless man, despite all the teasing and the jokes Tony wasn’t one for lying. Sure, he had the ability to lie, but Amajiki could tell that that Tony was being truthful.

“Well… I suppose that makes it easier…” Amajiki looked down not sure what to say. Tony laughed patting Amajiki’s back at Bruce gave a slightly mused snort going back to his work. 

/////

After leaving the lab, Amajiki walked through the halls deep in thought. Should he confess now or be cliché and wait? He thought maybe that he should consult Hado and Mirio. The two of them had more experience with confessing and getting turned down than him so it was worth a shot to ask them. He quickly found his friends talking to Steve Rodgers.

“Amajiki, good to see you.” Steve was the first to notice him.

“Mr. Rodgers.” Amajiki bowed his head. “H—Hado can we talk for a minute?”

“Sure, thing Amajiki!” She grabbed him by the arm dragging him to another room. “So, what’s up?”

“I—I want to ask Eijiro out officially.”

“What do you mean by “officially”?”

“Well you see during his first time at the work study, he got hurt and scared me, so he made it up to me by taking me to lunch. And then after the whole Hassaikai he promised me dinner as an apology.” Amajiki explained.

“Oh, I see. Well if you want to make it an official date tell him how you feel and say I want to make that “apology dinner” a date.” Hado said simply. “Come on, he’s really taking you to dinner, so this is your chance.” She encouraged him. Before he could say anything Hado began pushing toward the HARM room excitedly. He gulped softly as he walked into the room seeing Kirishima train with Fat Gum. Amajiki blushed heavily at the sight of his crush covered in sweat. Why did the younger classman have to look so hot? Clearing his throat, he called over to Kirishima.

“Oh, hey Tamaki. What’s up? Did Izumi come back?” Kirishima asked.

“N—No I wanted to talk to you about something.”

“Sure. What is it?” Kirishima asked eagerly.

“I … I was…. I was wondering if—if you’d mind turning that “apology dinner” into a date.” Amajiki said blushing redder than the reddest of red roses.

Kirishima also blushed red and said, “S—Sure. I’d really like that. How about tomorrow I’ll ask Mr. Stark if we can barrow the Quinjet. Leave around 6 get back at 8 maybe 9?”

“S—Sounds good.” Amajiki said looking away slightly. Ten minutes late after leaving the HARM Room, Nejire was ecstatic and told Mirio what happened. When Mirio heard he too was overly ecstatic much to Amajiki’s chagrin.

“When are you going to ask Rodgers out?” Amajiki asked getting the pressure off him. Nejire looked at Mirio with the same look she gave Amajiki when he decided to change the “apology dinner” into a date.

“He’s got a point Togata. So, when are you going to ask sweet little Rodgers out?” She looked at him with mischievous eyes.

Mirio panicked his face going red as he stuttered, “W—W—What!? No! I can’t ask her out!”

“Why not? You both got so much in common. I mean you’re both so bright and cheerful.”

“And you both have a connection with Sir Nighteye.” Amajiki added.

“But there is no way Sir, the Avengers, or especially Mr. Rodgers are going to let me ask Izumi out.” Mirio explained. “They’d kill me for sure.” 

“What this about asking Izumi out?” Asked Rhodey peeking his head in.

“War Machine I have a question,” Nejire walked over to him before Mirio could stop her. “If Togata asked Izumi out on a date would you object?”

Rhodey looked thoughtful for a minute and said, “No I mean if it’s a first date then I wouldn’t mind it. But that’s a question for Steve.”

“Right.” Nejire nodded. “Mr. Rodgers, I have a question!”

“NEJIRE NO!” Mirio shouted running after her.

/////

Mirio had a sick feeling in his stomach having heard nothing from Izumi. Nighteye and Steve seemed to have the same sick feeling in their stomachs. Mirio searched the tower high and low and hadn’t found Izumi. Maybe she was still with Fury? Mirio walked up to the room were the Avengers usually spoke with Fury. By the time he reached the area he saw that Steve and Nighteye where already there. Mirio had been studying English and while he couldn’t speak it very well, he could understand what they here saying.

**“Sorry Captain, I haven’t seen Izumi since she contacted me.”**

**“Which was when?”**

**“Two hours ago. She asked to head to Earth. Something about a bad feeling and she went to find Strange.”**

“Dr. Strange?” Nighteye questioned getting a nod from Steve. Mirio who was hiding behind the door turned away from the room looking deep in thought. Something was wrong. And must have been serious if she was looking for Strange. Mirio left the door he was hiding behind, changed into his hero costume, and raced to the hanger. It was pretty easy to get his hands on a Quinjet. Everyone in the hanger and FRIDAY had seen him but even so he walked up to the closest Quinjet activated the auto-pilot and took off. It should not have been that easy. Mirio soon forgot about it and focused on finding Izumi. Mirio noticed the auto-pilot stealth mode had kicked in as the jet began entering the atmosphere. 

/////

Arriving at the home of Dr. Strange didn’t take long. Mirio had the jet land on the roof and walked out. He permeated through the door leading into the Sanctum and called to Izumi and Dr. Strange. Neither of them where responding. Mirio wasn’t like this. Venturing deeper and deeper into the Sanctum, Mirio noticed all the objects that Dr. Strange had in cases. It was like walking into a museum. He made his way down the stairs in the front area before the door seeing Izumi talking with Strange as Goose sat beside her. That cat really did follow her everywhere.

 **“Are you absolutely sure about this Izumi?”** Asked Strange worried.

 **“Thor is going to need all the help he can get if I’m right.”** Izumi answered. **“Odin once told me about his firstborn of which he had locked away because her ambitions of conquest grew far too great to subdue. And if he dies there is no telling what she could do.”** Mirio looked confused, wasn’t Thor the firstborn of Odin? And she had spoken to Odin once? How?

 **“You spoke with Odin? How?”** Asked Strange.

 **“Thor may or may have not taken me to Asgard on one the days he was asked to baby sit me.”** Izumi played it off as Mirio and Strange shared a shocked expression. Izumi had been to Asgard!? Mirio was so going to ask her all about it. It was during Mirio’s excitement of asking Izumi about Asgard that he noticed that Strange wasn’t wearing his cloak. What was it? Suddenly Mirio felt himself getting grabbed by something and thrown down to the ground.

“MIRIO!?” Izumi shouted.

Mirio gave a small nervous laugh, “H—Hey Izumi. I know so uncool to eavesdrop like that, but I was sent by Mr. Rodgers to find you. He was getting worried.”

“Wow lying to a telepath.” Snorted Strange.

“Well it isn’t a total lie. Mr. Rodger is worried about you.” Mirio defended.

Izumi sighed softly, “I know he is. But I’m not a little kid and more. I am an Avenger and I can make my own choices.”

“I didn’t say anything to indicate that. But you can’t just go rushing off without telling anyone what you’re thinking especially knowing that Thanos is coming thinking you’re the Infinity Stones.” Mirio argued.

“I am aware of that Mirio. But right now, need to focus on now. And “now” is the return of Odin’s firstborn.”

“I thought Thor was…”

“He isn’t.” Izumi shook her head. “The Goddess of Death, Hela, is the firstborn of Odin.”

“The Goddess of Death!?” Mirio shouted shocked. Izumi nodded again.

“Strange can you open a portal to Thor and Odin’s location?” Izumi asked.

“Of course.” Strange said opening a portal.

“You’re coming with me Mirio.” Izumi said grabbing him by the cap. Mirio sighed as Strange’s cloak waved him goodbye. Mirio glared at the cloak as Goose walked beside him as they walked through the portal. **“Thor!”** Izumi called out seeing Thor sitting with Loki. **“Thor, Loki where is…?”**

 **“He is with mother.”** Loki answered and Izumi looked upset as did Goose. Mirio standing upright looked around as the portal they used vanished. Mirio went over to Thor and patted his shoulder getting a thankful smile from the God of Thunder. But the peace they experienced was cut short by a portal opening. Goose’s back arched as Izumi got ready to fight. A woman wearing torn black body suit walked out of the portal.

 **“So, he’s gone.”** Said the woman. **“About time.”**

 **“So, you’re Hela Odin’s first born.”** Said Thor. 

**“And you both must my little brothers.”** Hela noted. **“And the two of you?”**

 **“I am Infinity Girl, and this is Lemillion.”** Izumi introduced.

 **“And you have a Flerken with you. How cute. I always wanted one.”** Hela said.

 **“Like anyone would follow you.”** Said Loki.

 **“You sound like father.”** She said.

 **“Let’s get this over with.”** Said Thor.

 **“You smell and look like him.”** Hela noted. Hela then brushed her hands back created a helmet with spider like spikes crowning in the back. She summoned two swords and charged.


End file.
